What mechanism distinguishes microevolution from macroevolution?

Question

It has been suggested that the two operate by different properties:
http://answers.yahoo.com/question/index;_ylt=ArN2aEefIqwWsRv9ZvvEZk7d7BR.?qid=20070816132746AAi1CrA

Can anyone establish a clear distinction between the two based on process rather than scale?

Answer 1

there isn't one. microevolution is process, macroevolution is pattern (universal common descent?).

if you're talking about creationist definitions, well macroevolution is that degree of change that has not been directly observed in the present. 'were you there' and so on. notice how this definition allows moving the goalposts when new evidence comes in - some creationists will always be 'skeptical' of evolution until science can explain every last atomic motion over the last 4.5 billion years that lead to humanity.

Answer 2

Microevolution is a small change which occurs over several generations to help a species deal with current environmental/other conditions (e.g. better natural immunity to diseases and other inherent traits)

Macroevolution is a large scale evolutionary change (e.g. may result in the development of a new species)

Definitions:
Macro = large-scale
Micro = small-scale

Hope this helps,
NiceFella ;)

Answer 3

There is no mechanism. Macroevolution is simply microevolution over a long, long period of time. Microevolution + time = Macroevolution.

Answer 4

to those who argue against evolution, microevolution is natural selection, and macroevolution is speciation taken a bit further to produce something that is radically different, not just unable to interbreed, Hybrid speciation I believe it's called, producing a new phenotype.

Answer 5

Time. Macro-evolution is micro-evolution occurring over millions of years.

Answer 6

When there a new breed of dog that's micro-evolution. When a dog gives birth to kittens that's macro-evolution.

Answer 7

There is no differentiation by a physcial or chemical process.

Evolution ("micro", "macro") is evolution .